Deploying Cisco® Voice over IP Solutions

Typical uOne Call Flows 365

protocols: POP3, IMAP4, or HTTP. The following steps summarize how the client retrieves

a message:

Step 1 Queries DNS to find the IP address of the server.

Step 2 Establishes a TCP/IP connection to the server.

Step 3 Optionally establishes an SSL connection to the server.

Step 4 Establishes a POP3, IMAP4, or HTTP connection to the server to retrieve

the message.

uOne uses IMAP4 for storage and retrieval of messages from the messaging server.

A typical IMAP session is summarized in Figure 9-4.

Figure 9-4 IMAP session.

Typical uOne Call Flows

This section discusses the following typical uOne call flows:

• Subscriber does not answer call.

• Caller leaves a message for a subscriber.

• Subscriber is notified to retrieve messages.

Connect

Service ready

Login

Login complete

Select

Select response

Select complete

ServerClient

Fetch

Fetch response

Fetch complete

Logout

Bye

366 Chapter 9: Unified Messaging

• Subscriber calls the UM server to retrieve messages.

• Inbound fax message to a subscriber.

• Printing a fax message from a subscriber’s mailbox to an alternate fax number.

• Overall uOne protocol flow sequence.

Subscriber Does Not Answer Call

When someone calls a subscriber and there is no answer, the call is forwarded to the

gateserver. When the local exchange carrier (LEC) switch detects an incoming call that is

destined for a busy or non-answering party, the switch formulates a Q.931 setup message

with the redirected number (RDN) field set to the original destination number, and sends it

to the gateway. The called-party number of the setup message is set to one of the DNIS

access numbers of the gateway. The original called number is then the RDN, and the

number that was called to access the server is the DNIS. Whenever the RDN field is

populated, the UM application uses it to retrieve (using LDAP) the subscriber’s profile from

a directory server. If there is a matching subscriber, UM retrieves and plays the subscriber’s

personal greeting. Figure 9-5 shows an example of how this process works.

Figure 9-5 Retrieve subscriber’s personal greeting.

In this example, the presence of RDN indicates a call to the subscriber. The UM searches

for the subscriber profile using 6018881234, retrieves it, and plays the personal greeting.

When a subscriber calls the UM server to access messages, automatic number identification

(ANI) is set to the calling number, DNIS is set to the called number, and RDN is not

populated. In this case, UM plays the general welcome message and requests the caller’s

phone number and PIN. A subscriber calling from his or her own phone can simply press

the # key, in which case UM uses the ANI to retrieve the subscriber’s profile, as shown in

Figure 9-6.

Calling number

6019991234

Access number

6017771234

ANI=6019991234

DNIS=6017771234

RDN=6018881234

UM Server

H.323 Gateway

LEC switch

Call forward

on busy or

ring no answer

Called number

6018881234

PRI

IP

Typical uOne Call Flows 367

Figure 9-6 ANI profile retrieval.

In this example, an unpopulated RDN field indicates a call from the subscriber to retrieve

messages. The UM requests that the subscriber enter his or her phone number or simply

press #. If the subscriber enters a phone number, it is used in a directory search (LDAP). If

the subscriber enters #, 6016661234 is used to search the directory for his or her profile.

Caller Leaves a Message for a Subscriber

When someone calls a subscriber’s phone number and does not get an answer, the

subscriber’s switch forwards the call to the Cisco AS5300 gateway. Figure 9-7 shows how

the messaging server accepts and routes a message to the subscriber.

Figure 9-7 User calls and leaves a message.

Calling number

6016661234

Access number

6017771234

ANI=6016661234

DNIS=6017771234

RDN=

UM Server

H.323 Gateway

LEC switch

PRI

IP

9

14

12

17

19

Disk store

1

Q.931 H.323

3

DS Routing table

16 178

2

15 181374

9

1

PSTN

15 181376

Agent Monitor Manager

10 LDAP20 SMTP

5

Schedule table

IMAP 11

Messaging

Server

UM Agent

Directory

Server

Call/Media Agent